Three-dimensional cage zinc triazine framework compound: Fluorescence sensing of aromatic compounds containing NO2/OH groups

Abstract

A new compound {[Zn₇(DPOT)₂(H₂O)₁₁]·2OH·3H₂O·5DMA} (1) was synthesized by the reaction of the H₆DPOT ligand (H₆DPOT= 5,5′,5′′-((1, 3, 5-triazine-2,4,6-triyl)tris(oxy)) tri-isophthalic acid, DMA= N,N-dimethylacetamide) and Zn(NO₃)₂·6H₂O using a solvothermal method. It was characterized by elemental analysis, infrared spectroscopy, ultraviolet spectroscopy, thermogravimetric analysis and X-ray powder diffraction. The crystal structure of 1 was determined by X-ray crystallography diffraction. The three-dimensional cage structure is formed by [Zn₂(COO)₄(H₂O)₂] and [Zn₂(COO)₃(H₂O)₄] building blocks. By exploring fluorescence sensing on nitro aromatic compounds (NACs) and hydroquinone (HQ), the results show that 1 has a smart fluorescence sensing ability for NACs and HQ. For HQ, the K_sv was 2.9 × 10⁴ M⁻¹, and the limit of detection (LOD) value was 9.5 μM. For 2,4,6-trinitrophenol (TNP), the K_sv was 2.4 × 10⁵ M⁻¹, and the LOD value was 1.12 μM.